Which environmental factors favor the development of Gray Snow Mold?

The development of Gray Snow Mold is significantly influenced by environmental conditions, particularly the presence of heavy snow accumulation combined with certain grass growth characteristics.

When tall turfgrass remains covered by thick snow, it creates a conducive environment for the fungus responsible for Gray Snow Mold, specifically Typhula incarnata and Typhula ishikariensis. The snow acts as an insulator, maintaining a cool moisture-rich environment that promotes the growth and spread of the fungi. Tall grass can also trap more moisture and organic matter under the snow, which further supports mold development.

In contrast, the other choices feature environmental factors that do not facilitate the growth of Gray Snow Mold. For instance, high temperatures and dry conditions would hinder fungal development, as would reduced soil nutrients and areas with compacted soil that do not support healthy turf growth. Increased sunlight can dry the grass and reduce moisture, thus limiting conditions that could lead to mold proliferation.